Technical Field
This invention relates generally to large transport vehicles such as tractor trailers, buses, and trains including locomotives and rail cars. More particularly, this invention relates to fluid couplings, both air and liquid couplings, for fluid systems, such as air brake systems, on large transport vehicles. Specifically a portable device is disclosed which is engageable around a fluid coupling; and the device includes a heating assembly for warming the coupling so that fluid may readily flow therethrough in cold weather.
Background Information
Large transport trucks, trains and other equipment with trailers or rail cars often require a physical connection to activate the air braking in the towed trailer or rail car. For connecting flexible air lines in transport trucks to their trailers, or from a locomotive to the rail car, the universal standard device is a hermaphroditic coupling called a “glad hand”. The air lines going to the glad hands are typically fabricated from plastic or rubber so that they are able to flex between the truck and trailer or rail cars and the locomotive as the vehicles move. A first glad hand is secured to the truck or locomotive. This first coupler is operatively engaged with the air brake system on that truck or locomotive. A second glad hand is secured to an end of a hose extending outwardly from the trailer or the rail car. The hose is operatively engaged with the air brake system on that trailer or rail car. Each of the first and second glad hands includes a rubber seal to prevent air from leaking from the system. When it is desired to connect the glad hands together, the couplers are oriented at right angles relative to each other and the seals are pressed together. One or both of the first and second glad hands is then rotated relative to the other. This rotational motion locks the glad hands together, thereby connecting the air brake system in the tractor to the trailer; or in the locomotive to the rail car. This system is also used to connect the air brake system of one trailer or rail car to the air brake system of another trailer or rail car.
Glad hands couplers are typically fabricated from aluminum die cast or other metal and they have narrow internal passageways when compared to the size of the inside diameter of the air hoses to which they are secured. Some glad hands are bolted to the rear of the truck cab or locomotive and in other applications both of the glad hands couplers are attached to hoses. Some vehicle mounted models also have shut off valves to close off the couplers when they are not connected together.
When glad hands couplers are used in cold climates where the temperature can be well below freezing, the aluminum glad hands get much colder than the air hoses to which they are connected. This can lead to a reduction in the braking capacity of the trailer because the air in the hoses and brake lines always includes some moisture, even though systems are set up to try and remove all moisture. The moisture in the system tends to collect in the passageways in the glad hands because they are narrower. Because the glad hands are fabricated from metal, any accumulated moisture tends to freeze, thereby narrowing the diameter of the passageway. This restricts the quantity of air that is able to flow through the passageways. Air brakes operate in such a manner that when insufficient pressure is built up in the system, the brakes tend to not release. As a vehicle travels through cold weather, the loss of air flow through the narrowing passageways of the glad hands will tend to cause the brakes to be applied or become slow to react. This naturally poses a potentially catastrophic danger to the vehicle. Additionally, the colder the temperature, the more difficult it is for an operator to connect glad hands together or to disconnect glad hands from each other.